Bitrix + Kontur.Elba Integration: Automated Invoicing

Elba is a cloud service for tax accounting for sole proprietors on the simplified tax system and patent. Unlike MoeDelo and Kontur.Accounting, Elba is tailored for micro-businesses with simplified operations. Elba's API provides access to documents (invoices, acts) and counterparties, but not payment management. This defines the possibilities and limitations of integration with Bitrix.

We are a team with 10 years of experience in 1C-Bitrix development and certified "1C-Bitrix" specialists. Our integration solves the problem of automatic invoicing and acts from online store orders directly to Elba. Order a turnkey integration—we will take into account all the specifics of your business.

Problems We Solve

Manual invoice entry. Without integration, a manager manually copies data from Bitrix to Elba—errors, delays, lost customers. Our solution eliminates the human factor, saving up to 15 hours per week on data entry.

OAuth 2.0 without errors. Incorrect token caching leads to API blocks. We implement a correct Client Credentials flow with proactive refresh.

Elba API limitations. No payment API and request limits—we offer workarounds: webhooks from payment systems, a queue via Bitrix agents. This allows us to handle up to 1000 orders per day without blocks.

How to Set Up OAuth 2.0 for Elba

Authorization is performed using the OAuth 2.0 protocol (Client Credentials). For server integration, it is enough to obtain client_id and client_secret from the Elba dashboard.

class ElbaOAuthService
{
    private string $clientId;
    private string $clientSecret;
    private string $redirectUri;
    private string $tokenUrl = 'https://auth.kontur.ru/connect/token';

    public function getClientCredentialsToken(): string
    {
        // For server integration — Client Credentials flow
        $ch = curl_init($this->tokenUrl);
        curl_setopt_array($ch, [
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_POST           => true,
            CURLOPT_POSTFIELDS     => http_build_query([
                'grant_type'    => 'client_credentials',
                'client_id'     => $this->clientId,
                'client_secret' => $this->clientSecret,
                'scope'         => 'elba.api',
            ]),
            CURLOPT_HTTPHEADER => ['Content-Type: application/x-www-form-urlencoded'],
        ]);

        $response = json_decode(curl_exec($ch), true);
        curl_close($ch);

        // Cache the token for (expires_in - 60) seconds
        $this->cacheToken($response['access_token'], $response['expires_in'] - 60);

        return $response['access_token'];
    }
}

Elba API Client in PHP

class ElbaApiClient
{
    private ElbaOAuthService $auth;
    private string $baseUrl = 'https://api.e-kontur.ru/api/v1';

    public function request(string $method, string $path, array $data = []): array
    {
        $token = $this->auth->getCachedToken();
        $ch    = curl_init($this->baseUrl . $path);

        curl_setopt_array($ch, [
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_CUSTOMREQUEST  => $method,
            CURLOPT_HTTPHEADER     => [
                'Content-Type: application/json',
                "Authorization: Bearer {$token}",
            ],
            CURLOPT_POSTFIELDS => in_array($method, ['POST', 'PUT'])
                ? json_encode($data) : null,
        ]);

        $json     = curl_exec($ch);
        $httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        curl_close($ch);

        if ($httpCode >= 400) {
            throw new \RuntimeException("Elba API error {$httpCode}: {$json}");
        }

        return json_decode($json, true) ?? [];
    }
}

How to Automatically Issue Invoices from Bitrix?

The main scenario: when an order is created, we automatically generate an invoice in Elba and send it to the customer by email. To do this, we first find or create a counterparty by INN, then form an array of product items.

public function findOrCreateCounterparty(\Bitrix\Sale\Order $order): string
{
    $props = $order->getPropertyCollection();
    $inn   = $props->getItemByOrderPropertyCode('INN')?->getValue();
    $email = $props->getUserEmail();

    if ($inn) {
        // Search by INN
        $list = $this->client->request('GET', '/counterparties?inn=' . urlencode($inn));
        if (!empty($list)) {
            return $list[0]['id'];
        }
    }

    // Create counterparty
    $isLegal = !empty($inn);
    $payload = $isLegal ? [
        'fullName' => $props->getItemByOrderPropertyCode('COMPANY')?->getValue() ?? '',
        'inn'      => $inn,
        'kpp'      => $props->getItemByOrderPropertyCode('KPP')?->getValue() ?? '',
        'email'    => $email,
    ] : [
        'fullName' => $props->getBuyerName(),
        'email'    => $email,
        'type'     => 'individual',
    ];

    $created = $this->client->request('POST', '/counterparties', $payload);
    return $created['id'];
}

public function createInvoiceForOrder(\Bitrix\Sale\Order $order): array
{
    $counterpartyId = $this->findOrCreateCounterparty($order);
    $items = [];

    foreach ($order->getBasket() as $item) {
        $items[] = [
            'name'     => $item->getField('NAME'),
            'count'    => $item->getQuantity(),
            'price'    => $item->getPrice(),
            'unit'     => 'pcs.',
            'ndsRate'  => 'NoNds', // USN — no VAT. Options: Nds0, Nds10, Nds20
        ];
    }

    // Delivery as a separate item
    $deliveryPrice = $order->getField('PRICE_DELIVERY');
    if ($deliveryPrice > 0) {
        $items[] = [
            'name'    => 'Delivery',
            'count'   => 1,
            'price'   => $deliveryPrice,
            'unit'    => 'service',
            'ndsRate' => 'NoNds',
        ];
    }

    $invoice = $this->client->request('POST', '/invoices', [
        'number'          => $order->getField('ACCOUNT_NUMBER'),
        'date'            => date('Y-m-d'),
        'counterpartyId'  => $counterpartyId,
        'items'           => $items,
        'comment'         => 'Order from website #' . $order->getField('ACCOUNT_NUMBER'),
        'paymentDueDate'  => date('Y-m-d', strtotime('+3 days')),
    ]);

    return $invoice;
}

What Limitations Does the Elba API Have and How to Work Around Them?

No API for payment registration. When an order is paid in Bitrix, you cannot automatically mark the invoice as paid in Elba through the API. Workaround: webhook from payment systems → email notification to the accountant with the invoice number. Or use Elba's bank integration—when money arrives in the account, Elba itself matches the payment with the issued invoice.

API limits. The Elba API has request rate limits. For a store with a large number of orders—a send queue via \Bitrix\Main\Agent or a separate worker.

Only invoices and acts, not waybills. For goods shipment, an act document is not entirely legally correct. For sole proprietors on USN, this is usually not critical, but for LLCs—consider Kontur.Accounting.

Act of Completed Work for Services

For services (not goods), we generate an act instead of an invoice:

public function createActForOrder(\Bitrix\Sale\Order $order, string $counterpartyId): array
{
    // Similar items structure
    return $this->client->request('POST', '/acts', [
        'date'           => date('Y-m-d'),
        'counterpartyId' => $counterpartyId,
        'items'          => $this->buildItems($order),
        'comment'        => 'Services for order #' . $order->getField('ACCOUNT_NUMBER'),
    ]);
}

Service Comparison

Elba is better for micro-businesses, but it falls short of Kontur.Accounting in functionality—the latter has payment and waybill APIs.

Field Mapping: Bitrix → Elba

What Is Included in the Work

We provide a ready-made turnkey solution:

• OAuth 2.0 integration with token caching
• PHP client for the Elba API
• Counterparty search and creation
• Automatic invoice generation on order creation
• Error handling, logging, retries
• Documentation and staff training
• 3-month warranty on correct operation

Work Process

1. Analysis—we study your document flow, identify integration points.
2. Design—we develop the architecture, agree on the stack (PHP version, Bitrix).
3. Development—we write code, configure agents, test on a staging environment.
4. Testing—we check the full cycle: order → invoice → payment → notification.
5. Deployment—we roll out to the production server, monitor the first days.

Timelines and Cost

Timelines: from 2 to 4 weeks depending on complexity (availability of atypical fields, non-standard payment scenarios).

Integration typically pays for itself within 3 months due to manager time savings. Get a consultation from an engineer—we will calculate the exact cost and timeline for your project.

Official Elba API documentation is available at https://api.e-kontur.ru.

CommerceML: Why Standard Exchange Is Both a Lifesaver and a Trap

Standard exchange via CommerceML 2.0 on typical "Trade Management" or "Comprehensive Automation" can be set up in a day or two. Products, prices, stock, orders—all via XML files on a schedule. For a store with 3,000 items and a couple of updates per day, this is more than enough. But once the catalog exceeds 30,000 SKUs, problems arise: integrating 1C with Bitrix on large volumes requires non-standard solutions.

Why does CommerceML slow down with catalogs over 100,000 items?

bitrix_1c_exchange.php generates XML on the Bitrix side, and 1C retrieves and parses it. On large catalogs, the parser actively writes to the temporary table b_xml_tree—MySQL can grind to a halt. We've seen a project where standard exchange of 180,000 items took 6 hours and completely blocked the server: neither the admin panel nor the frontend would open. The solution is incremental exchange. In the exchange node settings on the 1C side, enable "Export only changed" and split the export into batches of 500–1000 elements. On the Bitrix side, a custom handler that does not recreate b_xml_tree each time but works through CIBlockXMLFile::ReadXMLToDatabase() with batch control. A catalog of 200,000 SKUs updates in 8–12 minutes.

Another pitfall is EXTERNAL_ID. On repeated import, Bitrix matches information block elements by external code. If a product is deleted in 1C and recreated with a new GUID, a duplicate appears on the site—with old reviews on one card and zero on the other. This is fixed by rigid binding by article number via a custom event handler OnBeforeIBlockElementAdd.

How to avoid duplicates during repeated import?

We bind products not by GUID but by article number. Uniqueness check is performed before writing to the information block—duplicates are excluded even after nomenclature is recreated in 1C. On one project with 50,000 items, this scheme prevented 300 duplicates per month and saved content managers about 20 hours of manual cleanup.

Custom 1C Configurations: When CommerceML Falls Short

"We have a standard configuration"—says every second client, and then we open the database and see 200 custom processing routines, renamed attributes, and custom sales documents. CommerceML works with a fixed XML structure. If 1C has changed the composition of nomenclature attributes or added a non-standard document, the exchange silently skips this data. Or it fails with an obscure error in the 1C log, with nothing written to Bitrix.

In such cases, we implement custom export. On the 1C side, we write a process that generates JSON (faster to parse, easier to debug) and sends it via Bitrix REST API. Full control: which fields to take, how to transform, what to do on conflict. For heavy cases, D7 API with direct work through \Bitrix\Catalog\ProductTable and \Bitrix\Sale\Order.

What are the key steps to set up 1C integration?

Custom REST is justified when:

• Non-standard nomenclature attributes;
• Multiple price types (retail, wholesale, dealer, promotional, regional, currency)—standard exchange sends only one type;
• Multi-warehouse with different stock levels and need to select a warehouse on the site.

Prices, Stock, and Multi-Warehouse

Standard exchange can transfer one price type. In reality, there may be 15: each with its own buyer group and priority. Mapping between 1C price groups and Bitrix user groups is a separate engineering challenge. Especially when discounts overlap and you need to determine which price wins.

Multi-warehouse adds another layer: product is in stock in Moscow, out of stock in St. Petersburg, and "on order" in Novosibirsk. The site must show availability per location, allow selection of pickup points, and calculate shipping from the nearest warehouse where the product is physically available. The standard Bitrix warehouse module (catalog.store) handles display, but we write the "which warehouse to ship from" logic separately. For one manufacturing holding, we implemented a custom stock aggregator that calculated balance across 8 warehouses in 2 seconds—reducing shipping errors by 80%.

Orders and Document Flow

An order from the site goes to 1C, a sales document is created, goods are reserved. Statuses come back. The main nuance is partial shipment: the client ordered 5 items, 3 are in stock, 2 will arrive in a week. 1C creates two sales documents. Bitrix out of the box cannot split one order into several shipments—we extend the OnSaleOrderSaved handler to create child orders and synchronize statuses for each.

Documents in the personal account—invoices, acts, waybills from 1C—are served via REST; PDF is generated on the 1C side and cached on CDN. The buyer downloads not from 1C directly (that would kill the server) but from cache.

Batch import with portion control reduces MySQL load and prevents locks (source: Wikipedia).

Monitoring: Not "Set and Forget"

Exchange can silently break: the script ran, no errors in log, but 200 products didn't update due to invalid UTF-8 in the name. Or 1C changed the date format in an update—all prices came in as zero.

Minimum set we install on every project:

• Telegram alert if exchange time increases 3+ times from average.
• Stock discrepancy check: script compares b_catalog_product.QUANTITY with what 1C provides, and alerts when delta exceeds 5%.
• Dashboard: last sync, number of processed items, queue, errors.

For high-load projects, we add async queues on Redis or RabbitMQ. Exchange does not block the web server, data is not lost during temporary 1C outages. On one online store with 2 million orders per year, we implemented this scheme—recovery time after failures dropped from 3 hours to 10 minutes.

Linking with Bitrix24 for Document Flow Automation

If besides the site there is a corporate portal on Bitrix24, we link it too. Counterparties from CRM go to 1C, invoices from 1C appear in deal cards. The manager sees accounts receivable and mutual settlements without switching windows. Deal closed—documents generated automatically.

Payment received in 1C → logistician gets a task for shipment in Bitrix24. Goods shipped → manager sees notification. Automatic tasks based on events from 1C—via Bitrix24 REST API webhooks. This link reduces manual entry by 70% and eliminates forgotten shipments.

How We Set Up Integration: Step-by-Step Process

1. Audit of 1C Configuration. Review the structure of directories, documents, attributes. Identify custom modifications. Assess data volume (number of SKUs, orders, warehouses).
2. Design Exchange Schema. Agree on data set: products, prices, stock, orders, documents. Determine sync interval and mechanism—CommerceML or custom REST.
3. Configure Standard Exchange. Set up CommerceML, batch mode, binding by article. Verify data transfer correctness on a test catalog.
4. Extended Integration. For complex configurations, write custom handlers on both 1C and Bitrix sides. Incorporate multi-warehouse, multiple prices, partial shipment.
5. Monitoring and Warranty. Set up alerts, dashboard, documentation. Train operators. After launch, warranty support.

Timelines and What's Included

Work results include: documented exchange schema, configured synchronization scenarios, monitoring dashboard, operator training, and warranty support after launch. Pricing is calculated individually—it depends on the complexity of the 1C configuration, catalog size, and required automation level. We'll evaluate your project in 1 day—write to us, let's discuss. Order integration and get stable exchange in 1–2 weeks.

We have completed over 50 1C integrations for online stores and manufacturing companies. The team's average experience is 7 years, and we have certified 1C-Bitrix specialists. Our experience ensures that the exchange won't break in the first month and will run stably for years. For example, on a project with a catalog of 50,000 items, automation of exchange saved the client significant operational costs annually.

Contact us for a free audit of your 1C configuration—we'll find bottlenecks and offer the optimal solution.